Rick It is lame that loopback takes up an entire class A network right?
Chris On Fri, Apr 22, 2005 at 09:16:03AM -0700, Rick Carlson wrote: > John H. Robinson, IV wrote: > >[EMAIL PROTECTED] wrote: > > > >>I'm trying to understand what loopback interface is used for > >>and /how/ it is works. > > > > > >I'm not exactly sure how it works. But it looks like a network > >interface, except it never leaves the box. This means that a Linux(UNIX) > >box with no network interfaces (no ethernet, no phone line, no ISDN, no > >toekn ring,no nothing) can still do all those neat networking protocol > >stuff. > > > > > >>Anyone got any examples of how an app uses loopback interface > >>effectively?? > > > > > >Start a webserver. > >http://127.0.0.1/ > > > >Start an ftp server, > >ncftp 127.0.0.1 > > > >Start an X server > >DISPLAY=127.0.0.1:0; export DISPLAY > >(or setenv DISPLAY 127.0.0.1:0 for you *csh'rs) > > > > > >>I vaguely know it acts like a remote node without > >>actually being one. I'd like the details. > > > > > >Not sure what details you need. > > > >-john > > Quoted from: > > http://www.geekcomix.com/cgi-bin/classnotes/wiki.pl?UNIX01/The_Loopback_Interface > > Despite it coming from geekcomix the info is for real. It appeared in a > series of tutorials called Unix01 written by Sam Hart who was/is > affiliated with the Physics Department at the University of Arizona. > > /begin quote > The Loopback Interface > > The loopback interface is a special kind of interface that allows > applications and servers on your Linux machine to make connections back > to the Linux machine. There are a variety of reasons why you would want > to do something like this; you could be testing something out and not > wish to disturb anyone on your local network, you could be running a > server locally which will not have an external interface, or you could > have specific encrypted tunneling you wish to do with an application > that cannot natively support it. For the vast majority of Linux > networking applications to work, you must have a loopback device. > > Traditionally, the loopback interface is defined with the IP address of > 127.0.0.1, thus, when you sit down at any Linux (or even UNIX) machine > and connect to 127.0.0.1 you are connecting to the local machine. The > loopback interface is also traditionally called 'lo'. > > /end quote > > Rick > [EMAIL PROTECTED] > -- > [email protected] > http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list > -- _______________________________________ Christian Seberino, Ph.D. SPAWAR Systems Center San Diego Code 2872 49258 Mills Street, Room 158 San Diego, CA 92152-5385 U.S.A. Phone: (619) 553-9973 Fax : (619) 553-6521 Email: [EMAIL PROTECTED] _______________________________________ -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
